Determination of mass transfer resistances in trickle bed reactors

A methodology for determining the mass transfer resistances of three-phase reactions in trickle bed reactors is presented. The hydrogenation of styrene over Pd/C was used as a case study to demonstrate the methodology. The gas-liquid mass transfer resistance was experimentally approximated by changing the palladium content of the bed while the chemical reaction resistance was calculated by using the observed chemical reaction rate constant which has been experimentally approximated in two different stirred tank reactors by hydrogenating the same compound under the same temperature and using the same solvent and active catalytic metal. The liquid-solid mass transfer resistance was calculated by subtracting the gas-liquid mass transfer resistance and the chemical reaction resistance from the overall resistance. The wetting efficiency of the bed was estimated from the experimental data and it was compared to the literature by using the dimensionless numbers of Re, Fr, Mo, Ga, We and Stk. The specific gas-liquid and liquid-solid mass transfer coefficients found in agreement with the literature.